Seconding sideshowalan's opinion of the stock unit. It was a dinosaur even in 2003 due to lack of AUX. It doesn't even have a cassette player to make up for its limitations!
But seriously, an AUX plug or USB input would be better, and they don't skip going over bumps when it's cold. You'd get access to a much bigger variety and might not have as many issues with file formatting. I even have an old Sony unit I could send you (I upgraded to an in-dash tablet setup).
"If you don't love me at my diddliest, you don't deserve me at my doodliest." - User ktluvscricket of reddit